Warning: this is an htmlized version!
The original is across this link,
and the conversion rules are here.
-- (find-angg ".emacs" "find-printindex")

p = "\171([!-~]+)\187[ \t]*%(to[ \t]+\"(.*)\"%)"

toindexline = function (anchor, pre, width)
    pre = pre or "% "
    width = width or 40
    local l = pre .. format("\171.%s\187", anchor)
    local r = format("(to \"%s\")", anchor)
    return format("%-"..width.."s%s", l, r)
  end

printindex = function (lines)
    for _,li in ipairs(lines) do
      local a,b = li:match(p)
      if a and "." .. a == b then
	print(toindexline(a))
      end
    end
  end

if arg and arg[1] == "-e" then assert(loadstring(arg[2]))() end
if arg and arg[1] == "-i" then printindex(splitlines(readfile(arg[2]))) end